For system-on-chip (SOC) applications, on-chip antenna helps integration and keeps the cost down, e.g., for millimeter wave wireless communication, WiFi, and telecommunication, etc. However, for a conventional patch antenna for millimeter wave communication, the performance is an issue with about only 5 dBi gain. Also, the large size of the on-chip patch antenna (e.g., 1.18 mm×0.89 mm for a 77 GHz application) and the antenna cost are problematic. Accordingly, new structures and methods are desired to solve the above problems.